GIMP Basics 2 – troubleshooting – When tools don't work

Link to the same video with better sound:

In this video I’m showing you some tips of what you can do when your tools don’t seem to work correctly or when they don’t seem to work at all. And also how to fix things when the menu item you want to use is greyed out.

Of course these tips won’t solve everything but they will solve the most comment beginner problems.